As the stock market benchmark Sensex races towards its 23,000-points milestone, at least 17 business houses have attained a market cap of Rs 1 trillion or more, led by Tatas with a massive group valuation of over Rs 7 lakh crore.

These 17 business houses together command a cumulative valuation of close to Rs 35 lakh crore -- almost half of overall investor wealth of nearly Rs 75 lakh crore in the Indian markets, shows an analysis of latest valuation of all listed companies in the country.

Interestingly, Tata group commands a valuation that is greater than the combined market cap of its two nearest rivals -- HDFC group and Mukesh Ambani-led RIL group on the valuation charts. Tata group has more than 30 listed companies, while its most valued firm TCS also happens to be the country's most valued firm with a market value of over Rs 4.3 lakh crore.

The markets' 30-share benchmark index, Sensex, is currently trading near 22,700 points and has gained more than 10 per cent or over 2,500 points in the past three months, which traders largely attribute to expectations for a reforms-friendly and a stable government after the ongoing general elections.

The election results will be announced on May 16 and there are widespread expectations about Sensex achieving 23,000-point level by that time.

The ongoing rally has seen at least 17 business houses attaining a market value of Rs 1 lakh crore and more. On this list, Tatas are followed by HDFC Group (Rs 3.2 lakh crore), RIL group (Rs 3.07 lakh crore), ITC (Rs 2.7 lakh crore) and Infosys (Rs 1.8 lakh crore).

Among these, Adani group has witnessed a sharp rally in the past three months and the shares of its three listed companies (Adani Enterprises, Adani Power and Adani Ports) have soared ahead by 40-101 per cent. Their collective market value has grown by more than Rs 40,000 crore in this period to close to Rs 1.03 lakh crore now.

There are a few groups which have got just one listed company, while others have multiple listed companies. The PSU companies have not been included into the study, as they do not belong to any particular business group and have got government as their main promoters.

RIL group has got two listed companies, while HDFC has got three (HDFC, HDFC Bank